I have about 2,100 hours in the Pegase 101A, and I always looked at 80 knots (unballasted) as the speed where L/D really dropped off. (Or 90 knots when flying ballasted and at Max Gross Weight) Since I fly in New Mexico in relatively strong conditions, I tend to push those speeds even higher on occasion if conditions warrant. (I made a 500 km flight in 4 hours flat, launch to landing, which is an average of 67.5 knots. Factor in the tow and thermal climbs, and the average speed was obviously much higher.) On a strong, high altitude cloudstreet, 100+ knot cruise speeds are great fun. Naturally, trying to fly that fast in other parts of the country will ensure many introductions to (hopefully) friendly farmers.